Concerns about environmental pollution and fossil fuel depletion have increased demand for alternative clean energy solutions. The hydrogen fuel cell, and in particular the proton exchange membrane fuel cell (PEMFC), is one potential power source for future automobiles and stationary applications. The reaction in a PEMFC involves hydrogen molecules splitting into hydrogen ions and electrons at the anode, while protons re-combine with oxygen and electrons to form water and release heat at the cathode. Typically, a proton exchange membrane is used as a proton conductor in a PEMFC. A catalyst layer containing, for example, platinum and/or a platinum alloy is used to catalyze the electrode reactions. A gas diffusion layer, which may include a microporous layer and a carbon fiber based gas diffusion backing layer, is used to transport reactant gases and electrons as well as remove product water and heat. In addition, a flow field plate is generally used to distribute the reactant gases.
Excessively cold or hot fuel cell temperatures may affect the membrane and other materials in the stack. Fuel cell systems typically include thermal management systems to control the temperature of the fuel cell stack within a desired temperature range.